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bad smell


sharif101
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Flight deck bad smell.when no 3 eng bleed valve close then no bad smell.this is new engine.5th & 10th stage bleed valve open & check no oil flashing inside the compressor.speed sensitive valve 14th stage bleed line check & no oil found.please give any idea.

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Fuel nozzle leakage.

New Engines or those with newly overhauled fuel nozzles sometimes experience this.

We found that our overhaul facility was not doing all the checks on the nozzles they were sending us, so we were getting back nozzles that would lead around the head and make the air-conditioning smell really bad.

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Ok, maybe this old mind is having some issues but fuel nozzles being the cause for a bad smell from the AC escapes me.

Air goes through compressor, then into the diffuser section where it slows down and bleed air is piped off, then into the burner cans where it mixes with fuel and ignites, then through turbine and out the back. With the fuel nozzles being aft of the diffuser section, and air flow moving aft, how can they cause the bad smell in the bleed air system?

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The inlets for the air coming off the diffuser are on the aft side of the diffuser struts, immediately adjacent to the fuel nozzles. With air trying to travel to an area of high pressure to an area of low pressure, you essentially have three vacuum cleaners trying to suck the fuel off the fuel nozzles. This is almost guaranteed if the fuel nozzle neck is cracked. Typically there is too much airflow to allow the flow of fuel orifice to go sideways, but it is possible because of the proximity of the bleed air inlet points on the diffuser struts, especially in LSGI where the open 5th and 10th bleed valves increase the turbulence and decreases the air velocity within the diffuser, and the secondary orifice is receiving less pressure than normal, disrupting the spray pattern.

I hesitate to say it is fuel nozzles though. If you have jet fuel vapors coming out of the A/C ducts, it will be very obvious it is jet fuel and not hydro or oil. There will be no doubt. If it doesn't smell like fuel, don't pull the fuel nozzles.

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Have the crew chief dump the honey pot

Where I come from, Crew Chiefs don't do piss, puke, or shit. If you were not man enough to control your bodily functions, you cleaned it up. A much safer bet than having the Crew Chief return it to you later......

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We were TDY from Rhein Main to RAF Sculthorp once and had a plane pre flighted, locked and sealed. It sat in the sun locked up for a day or two, must have been the only time the sun ever came out in England, HOT. Well, unbeknownst to any one, a specialist used the honey bucket before the plane was locked. Talk about ripe!!! As I recall it was made a big deal of and the plane was even late for launch after the crew wouldn't take it until they found the specialist and made him clean the honey bucket out.

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Please forgive my crew chief remark. It was actually a tongue in cheek comment. Everyone knew, if you used it, you cleaned it. I'm sure the majority of folks would rather pucker their butt cheeks on those long overseas flights rather than "maintain" the bucket. I know I never used it!

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Please forgive my crew chief remark. It was actually a tongue in cheek comment. Everyone knew, if you used it, you cleaned it. I'm sure the majority of folks would rather pucker their butt cheeks on those long overseas flights rather than "maintain" the bucket. I know I never used it!

No worries. I wasn't twisted over the comment. Just keeping the discussion interesting.

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I worked for and retired from Grumman Corp.About a year before I left the company was selling E2C acft.to Taiwan and flight training crews, both cockpit and back enders. Those crews flat refused to dump the honey buckets after use. When I left the plane capts(crew chiefs) were still dumping them.

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The inlets for the air coming off the diffuser are on the aft side of the diffuser struts, immediately adjacent to the fuel nozzles. With air trying to travel to an area of high pressure to an area of low pressure, you essentially have three vacuum cleaners trying to suck the fuel off the fuel nozzles. This is almost guaranteed if the fuel nozzle neck is cracked. Typically there is too much airflow to allow the flow of fuel orifice to go sideways, but it is possible because of the proximity of the bleed air inlet points on the diffuser struts, especially in LSGI where the open 5th and 10th bleed valves increase the turbulence and decreases the air velocity within the diffuser, and the secondary orifice is receiving less pressure than normal, disrupting the spray pattern.

I hesitate to say it is fuel nozzles though. If you have jet fuel vapors coming out of the A/C ducts, it will be very obvious it is jet fuel and not hydro or oil. There will be no doubt. If it doesn't smell like fuel, don't pull the fuel nozzles.

We had an overhaul facility rebuilding our fuel nozzles, but they were not doing ALL the tests after the rebuild, so they were sending them back to us without a certain leakage check. After having to replace the nozzles a couple times for the fuel smell in the AC, we asked about their testing methods. They had to revamp their checklist to correct the leakage that was getting through inspection.

The smell is different from the one we get after a compressor wash. It isn't any more pleasant though.

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  • 7 years later...

Writing a book that has a C-130. Can anyone please tell me if there's normally hand sanitizer/sink of some sort to clean hands after using the honeypot? Just trying to keep it realistic. Thank you. 

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